Diesel fuels are available from a variety of sources with a variety of desirable and undesirable properties. Diesel fuel provides better lubricity than other petroleum fuels and the diesel engine offers more efficient combustion than a standard gasoline engine. Unfortunately diesel engines are frequently associated with increased pollution, including NOX, particulate, and other emissions. Direct-injection diesel engines can significantly increase fuel economy without sacrificing attributes and will likely meet or exceed increasing emission standards with additional improvements.
Diesel engines are a well established technology in Europe that captured over half of the passenger car market in model years 2007-2008 (Schmidt's, 2010). Developing a highly efficient diesel system with an efficient engine and quality fuel will lead to greater adoption of diesel fuels in the future. As diesel engines improve, they continue to reduce emissions, improve fuel economy, and decrease environmental impact.
Because diesel fuels are readily available from a variety of sources, petroleum based diesel (petrodiesel), renewable biological diesels (biodiesels), synthetic diesel, and others, diesel engines must be able to operate efficiently with a variety of different fuel sources. Diesels may be incorporated and blended to meet market needs, government standards, and higher environmental initiatives. Currently, the vast majority of diesel fuel is derived from petroleum sources although biofuels and synthetic diesels are being developed. Unfortunately, to date renewable biofuels and synthetic diesels are far too expensive to meet current diesel fuel requirements.
In order to meet ever increasing diesel emission standards, reduce fuel consumption, and meet current diesel fuel requirements, an inexpensive source of diesel fuel with low emissions is required.